/*
 * Copyright (C) 2020 The LINN Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License
 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.juqimiao.linn.config;

import com.juqimiao.linn.context.ApplicationContextWrapper;
import com.juqimiao.linn.context.ApplicationContextWrapperI;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableBeanFactory;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;
import org.springframework.core.annotation.Order;

/**
 * 配置Framework所需的Bean。
 * 目前主要构建和返回 {@link ApplicationContextWrapperI} Bean。
 *
 * @author Collin Cai
 */
@Configuration
@EnableConfigurationProperties(FrameworkProperties.class)
public class FrameworkConfig implements ApplicationContextAware {
    private ApplicationContext applicationContext;

    private static ApplicationContextWrapperI applicationContextWrapper;

    /**
     * Get the application Wrapper object.
     *
     * @return {@link ApplicationContextWrapperI}.
     */
    public static ApplicationContextWrapperI getWrapper() {
        return applicationContextWrapper;
    }

    /**
     * Override setApplicationContext to get the applicationContext object.
     *
     * @param applicationContext applicationContext.
     * @throws BeansException Throws BeansException.
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    /**
     * Get the singleton of {@link ApplicationContextWrapperI}.
     *
     * @return Return {@link ApplicationContextWrapperI}.
     */
    @Bean
    @Scope(value = ConfigurableBeanFactory.SCOPE_SINGLETON)
    public synchronized ApplicationContextWrapperI createWrapper() {
        if (FrameworkConfig.applicationContextWrapper == null) {
            synchronized (ApplicationContextWrapperI.class) {
                if (FrameworkConfig.applicationContextWrapper == null) {
                    ApplicationContextWrapper wrapper = new ApplicationContextWrapper();
                    wrapper.setApplicationContext(applicationContext);
                    FrameworkConfig.applicationContextWrapper = wrapper;
                    return wrapper;
                }
            }
        }
        return applicationContextWrapper;
    }
}
